This invention relates to the transport of portable structures, particularly portable toilets. Conventional portable or transportable structures such as portable toilet units are typically used at construction sites, outdoor public events and various other venues where a running water supply is unavailable. These structures generally comprise a housing within which a waste material storage tank is positioned. The housings of the portable toilet are usually made of large sheets of plastic materials which are formed into rear and side walls and a front wall having a doorway and a suitable door, a roof and a floor. The structures are typically light enough to be moved and/or loaded onto a trailer by one person who tips the structure down and slides it into place on the bed of a conventional flat bed trailer.
It is desirable to transport portable toilet structures in an upright position to minimize the likelihood that waste will leak from the collection tank into the interior portion of the housing. Towing one or more portable toilet structures on a trailer presents challenges, particularly in windy conditions due to the shape of the structures and the wind resistance exerted against the housing walls as they are towed at normal driving speeds behind a truck or a car. While wind diverters and other devices have been conceived to help reduce wind resistance while towing using trailers, these devices are clumsy and must be mounted to the towing vehicle or the trailer. Examples of wind diverters can be found in U.S. Pat. No. 3,596,974 to Adams, U.S. Pat. No. 3,695,673 to Meadows and U.S. Pat. No. 3,768,854 to Johnson et al.
Conventional flat bed and other trailer types are unsatisfactory or inconvenient to use for transporting portable toilet or other portable structures because there is no standardized element on a conventional trailer for quickly and easily securing the portable toilet structure to the conventional trailer. Also, the height or covered housing structure of a conventional trailer may make it difficult to load and unload the portable toilet structure. An example of a conventional flat bed trailer is disclosed in U.S. Pat. No. 3,731,831 to Huff. A standard trailer with a housing is disclosed in U.S. Pat. No. 4,807,894 to Walker.
Specialty trailers for towing portable structures are also known. Examples of such trailers are disclosed in U.S. Pat. No. 7,401,804 to Rupp, U.S. Pat. No. 4,653,125 to Porter and U.S. Pat. No. 5,548,856 to Julian.
It is desirable to provide a trailer for transporting one or more portable structures in which it is relatively quick and simple for a portable structure to be loaded onto, secured to and unloaded from a trailer. It is also desirable for the trailer to be designed such that the wind resistance incurred while towing the portable toilet structure at normal driving speeds, particularly on an interstate highway is reduced from the oncoming forward direction of the vehicle and for cross-winds from either side. The invention of the present application addresses these problems and provides an improved trailer for transporting portable structures.